A programme to retro fit all Greater London authority buildings will be put in motion by the end of the year, said deputy London Mayor Sir Simon Milton.
He told the London stand at MIPIM in Cannes that work to upgrade all 100 GLA buildings would begin next year.
He also announced that the Mayors office intended to extend the programme to all public buildings in the capital.
He said a procurement process would be launched before the end of 2009.
Milton said: 'We are in talks with public sector bodies to turn this into a much wider programme so that all of the public sector can take part.'